Dealing with a parent who says she wants to live, but won't get out of bed without a hassle.

I guess I haven't recently started being a caregiver, but the demands have gotten to be more and more. I moved in m-with my mother when I became a single parent. She helped me take care of my son and I helped with rent, housework and more. That has never been the issue. Many often asked how I could live with my mother. I always responded that my mother and I were close and were friends. We had our separate lives and helped each other as needed, so it worked. Five years ago, she was diagnosed with lung and throat cancer. She courageously went through chemo and radiation treatments and did better than anyone expected. She then ended up with Hypothyroid, which kind of pushed her over the edge. She did 'get better', but never has completely regained her endurance, strength and her independence has decreased gradually. I do have 4 siblings - three in the area; all who have helped as needed. The primary burden falls on my shoulders as my mom lives with my son and myself. We've made it work so far, but now I feel a greater burden and feel myself becoming more resentful. My son is progressively having a harder time dealing with his grandmother as well. Trying to balance the care of an ailing parent and the life of a 14 year old leaves me tired and worn out by the end of the day....oh and there is myself to care for as well, but this usually is pushed to the side. I guess the biggest issue I have now is trying to know when to push her and to when to let everything go. I give her her meds when needed, I prepare her food and assist her with dressing and care as needed. But every morning I have to ask nicely, then beg and then get mad to get her out of bed. At times, I do just walk by her door and let her go, but then I feel guilty to not get her up and make her eat and drink because ultimately, I have to deal with the repercussions in her fainting or falling. She has recently ended up in the hospital twice, with one 2 week stay at a rehab facility (of which she did not take full advantage!). She hasn't broken a hip yet, but it is always on my mind. Today, when I finally got her out of bed, she just gets mad and says that I have to be nicer....and then I feel my blood pressure go up. On top of it, because she did not manage her financial situation ahead of time, we are trying to find ways to limit huge losses in the case if she needed a nursing home as she would then need to spend her savings and then her house (which is also my house, but not in name....). So now I am facing the anger at myself for not having thought ahead about my own future and the future of my son. Like I said before, I am a single mother who works in a school district (which has been fantastic for flexibility) with no child support (another issue on another site!). Oh geez - I am all over the place with this question/topic, so my apologies. I guess I am looking for those who have dealt with taking care of an ailing parent in their home and have not completely gone crazy or have ulcers because of guilt. Oh - one more thing....my siblings are helpful, but then I even start to resent them as they walk into my mother/ my home like it is theirs....and then they get to walk out, alone and head to their home which is quiet and their own routine! Any words of advice or encouragement would be helpful. i guess I am happy to have come across this site...and having read many responses certainly know that I am not alone and may have found a place to vent to people who really understand the facts!